In the detail, it is possible to see pixel chessboard-like pixel structure. I can get rid of it in many ways (any kind of blur or averaging will do the trick). However, I would like to know where this structure origins. My ideas:
camera use colors by default - can the grayscale setting use the RGB sensors in the way that cause this?
could this be produced by compression or storing of the images? I have no information about how it is done - but the images are in PNG format when I get them.
As I said, I can homogenize the image, but I wonder, maybe there is something fundamentally wrong what we do and that should be fixed.